1. Field of the Invention
The present invention relates to a intelligent network system, and more particularly, to a traffic control method for intelligent network services which is capable of effectively controlling a traffic between a SSP(Service Switching Point) and a SCP(Service Control Point).
2. Description of the Background Art
FIG. 1 is a schematic view of a conventional intelligent network(IN) system.
As illustrated in FIG. 1, the IN system includes a service switching point(SSP) 10 and a plurality of service control points(SCP) 11-1 through 11-n.
The SSP 10 is a network element for detecting and executing an IN service. The SSP 10 generates a query required for service execution to the SCP 11-1 through 11-n by detecting the IN service, and executes the IN service according to the service control command of the corresponding SCP. In addition, the SSP 10 also executes a basic call processing function conductbd by a normal, such as the detection of the state of origination and destination sides:
The SSP 10 is connected to the SCP 11-1 through 11-n via a SS7 link 50 while being connected to a subscriber terminal 40 via a telephone line 30. Also, the SSP 10 is connected to another plurality of SSP(not shown) via a trunk(not shown) for transmitting communication signals, e.g., sound and/or data.
The SCP 11-1 through 11-n each are physical network elements for controlling an IN service. The SCP serves to generate a service control command to the SSP 10 by executing a service logic stored in a database upon receipt of an IN service request from the SSP 10.
The call gapping operation in the thusly constructed conventional IN system will be explained with reference to the accompanying drawings.
In the intelligent network(IN) system, calls are generally divided into intelligent network(IN) calls requiring a service request query from the SSP 10 to the SCP 12 and normal calls which are processed by the SSP 10 alone.
When a call is initiated from a service subscriber, the SSP 10 performs an appropriate call processing by detecting whether a subscriber call is an IN call or a normal call. That is, when a call is initiated from a service subscriber, the software of the SSP 10 detects an IN call and a normal call by referring to trigger data, and thereafter generates a query required for service execution to a specific SCP, e.g., the SCP 11-1 with respect to the IN call.
In other words, the SSP generates triggers in response to the activity in the subscriber station, for example, when the subscriber""s telephone is hooked off, the SSP 10 generates appropriate subscriber-related triggers. At this time, the nature and format of the triggers are standardized to the SS7(Signaling System7) protocol as already known.
The SSP 10 discriminates IN calls from normal calls by comparing the generated triggers with trigger criteria, and then generates a query required for the execution of the corresponding IN service by using the INAP(lntelligent Network Application Protocol). Thus, the SCP 11-1 performs a predetermined service logic according to the service query from the SSP 10, and then generates a service control command to the SSP 10, whereby the SSP 10 performs the processing of the corresponding IN service according to the service control command.
On the contrary, if the service subscriber""s call is a normal call, the SSP 10 processes the call according to a basic call processing procedure.
As described above, generally, the IN service generated by a local switch or a transit switch is processed by the SSP according to the control of the SCP. That is, the SSP generates a query required for the execution of the IN service to the SCP, and thereafter processes the IN service according to the service control command of the SCP,
However, if an excessive request for IN services is generated from the SSP to the SCP, an overload is generated on a signal link between the SSP and the SCP to thus generate a large amount of incomplete calls. In addition, also in the case that an overload is generated on the SCP due to an IN service request from an intelligent network switch, a large amount of incomplete calls are generated, is though there are sufficient signal links between the intelligent network switch and the SCP. Thus, a normal service control function is disabled, and even a service failure is occurred.
Therefore, when the above overload state is generated, the corresponding SCP 11-1 automatically performs a call gapping operation in order to the frequency of an accessed service request, or performs a manual call gapping operation for manually controlling overload according to a service operator""s request. That is, as illustrated in FIG. 1, when an overload is generated by a large amount of service A requests, the corresponding SCP 11-1 transmits a call gapping message(CGM) to the SSP 10 in order to control the overload state.
Consequently, the SSP 10 applies the call gapping operation according to the call gapping message(CGM). At this time, as illustrated in FIG. 1, the SSP 10 applies the call gapping operation for service A, not only to the SCP 11-1 by distinguishing between different physical nodes, but to all SCPs 11-1 through 11-n regardless of the different physical nodes of the SCP 11-1 through 11-n in the same manner.
In this way, in the conventional traffic control method for intelligent network services, the call gapping operation is applied by recognizing the group of SCPs as a single SCP irrespective of the physical nodes of the SCPs. As the result, in the case that the IN network is divided into a plurality of SCP groups later, the traffic control method for intelligent network services is disadvantageous in that it is impossible to control a call arrival at a specific node(SCP).
Accordingly, it is an object of the present invention to provide a traffic control method for intelligent network services which is capable of exclusively performing a call gapping operation by distinguishing between different physical nodes of each SCP.
It is another object of the present invention to provide a traffic control method for intelligent network services which is capable of controlling a call arrival by each intelligent network group when an intelligent network is divided into a plurality of groups.
To achieve the above objects, there is provided a traffic control method for intelligent network services according to the present invention, in an intelligent network(IN) constructed of a plurality of SCPs and more than one SSP group, which includes the steps of: directing a SSP to perform a call gapping operation by distinguishing between different physical nodes upon detecting an overload; and applying the call gapping operation only to the corresponding SCP by distinguishing between the different physical nodes of the SCP that has requested the call gapping operation based on a call gapping message transmitted from the SCP upon receiving an IN service request from a subscriber.
To achieve the above objects, the step of applying the call gapping operation includes the steps of: receiving an IN call from a subscriber; searching the SCP that has requested the call gapping operation by distinguishing between the different physical nodes of the SCP group upon receipt of the IN call; checking if the searched SCP has requested the call gapping operation or not; and, if the searched SCP has requested the call gapping operation, performing the call gapping operation by checking if the corresponding IN call satisfies the corresponding call gapping condition.
In addition, to achieve the above objects, there is provided a traffic control method for intelligent network services according to the present invention, in an intelligent network(IN) constructed of a plurality of SCPs and more than one SSP group, which includes the steps of: transmitting a call gapping message to a SSP by distinguishing between physical nodes upon detecting an overload: searching the SCP that has requested a call gapping operation by distinguishing the different physical nodes of the SCP group upon receipt of an IN call from a subscriber; checking if the searched SCP has requested the call gapping operation or not; if the searched SCP has requested the call gapping operation, checking if the corresponding IN call satisfies the corresponding call gapping operation or not; and, if the corresponding IN call satisfies the call gapping operation, performing the call gapping operation.
Additional advantages, objects and features of the invention will become more apparent from the description which follows.